Coinfection

Among HBV/HCV coinfected people, about half have dominant hepatitis B virus while half have dominant hepatitis C, and those with active HBV replication are at higher risk of liver-related complications and death, according to study findings presented at Digestive Disease Week this month in Chicago.

HIV positive study participants with hepatitis B virus (HBV) or hepatitis C virus (HCV) coinfection who had higher blood levels of biomarkers associated with impaired liver function and inflammation were more likely to die of non-AIDS-related causes, researchers with the SMART treatment interruption trial reported last month at the 17th Conference on Retroviruses and Opportunistic Infections (CROI 2010) in San Francisco.

Due to overlapping transmission routes, many people are dually infected with both hepatitis B virus (HBV) and hepatitis C virus (HCV).

In a poster presentation this week at the 48th International Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington, DC, Italian researchers presented data confirming prior research showing that the presence of HBV interferes with HCV replication.

The investigators performed long-term clinical and virological follow-up of 29 chronic hepatitis C patients with HBV superinfection and 29 HCV negative individuals with acute hepatitis B. Patients in the 2 groups were matched for age (+/- 5 years), sex, and HBV risk factors.

• Severe acute hepatitis B was more frequent in the HBV-HCV coinfected group than in the HBV monoinfected group (34.5% vs 6.9%; P < 0.05).

• Of the 28 patients in the HBV-HCV superinfection group who were still alive at the end of acute illness (1 died of sub-acute progressive hepatitis), 24 (85.7%) were followed for 2-6 years (median 5 years):

Due to the similar transmission routes, many people are dually infected with both hepatitis B virus (HBV) and hepatitis C virus (HCV). While the interaction between these 2 viruses is not fully understood, studies have shown that HBV seems to inhibit HCV replication and vice versa. As such, there is a risk that successful treatment of one virus could potentially lead to worsening or reactivation of the other.

In a brief report in the December 2008 European Journal of Gastroenterology and Hepatology, French researchers described a case in which an HBV-HCV coinfected patient was simultaneously treated with both interferon-based therapy for chronic hepatitis C and the FDA-approved anti-HBV drug adefovir (Hepsera).

The authors observed that HBV reactivation as the result of HCV eradication was prevented by treating both viral infections together.

This finding, they concluded, "raises the question as to whether preemptive HBV treatment should be prescribed along with HCV treatment to prevent HBV from being [reactivated] after HCV eradication in coinfected HBV-HCV patients."

Occult hepatitis B virus (HBV) infection has been reported in numerous clinical settings, but it remains unclear whether occult HBV contributes to liver damage. Given that typical chronic HBV infection is often characterized by periodic flares in viral replication and liver inflammation, investigators from Johns Hopkins School of Medicine hypothesized that occult HBV might also be associated with flares in viral replication that are associated with increased liver enzyme levels.